Washing liquid and drying air-heating means for dishwashers



Allg- 21, 1951 J. N. ALLENswoRTH WASHING LIQUID AND DRYING AIR HEATING MEANS FOR DIsHwAsNERs Filed Jami 25, 1946 3 Sheets-Sheet 1 WW A tiJI DR J. N. ALLENSWORTH WASHING LIQUID AND DRYING AIR HEATING MEANS FOR DISHWASHERS Aug. 21, 1951 3 Sheets-Sheet 2 Filed Jan. 25, 1946 ./M/fs M ALLE/vs woRTH [Nl EN TOR. z 9L ISI' BY Q7 M A ORNE YS 2 G` N I T A E H Tmm RAW

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A TT ORNE YS Patented ug. -21, 1951 WASHING LIQUID AND DRYING AIR-HEAT- ING MEANS FOR DISHWASHERS James N. Allcnsworth, Houston, Tex. Application January 25, 1946, Serial No. 643,217

4 claims. (ol. 134-60) This invention relates to machines for washing, drying and sterilizing dishes and like articles, and relates more particularly to a machine of the class described having a plurality of sections which are so constructed and arranged that the machine is extremely eilicient in eiecting desired results.

The primary object of the invention is therefore to provide a self-contained machine of the class described that is especially effective in cleaning and sterilizing the articles passing therethrough.

Another object is to provide a machine that is capable of handling a large volume of the articles to be cleaned.

Still another object is to provide a machine in which cleansing liquids are supplied successively at different temperatures to the articles, the temperatures being such as to most eectively contribute to the ultimate desired result.

A still further object is to provide a machine having successive sections in which operations such as pre-rinsing, washing, and sterilizing are carried out amid optimum conditions, and whereby effective cleansing and sterilization of the articles are brought about.

The invention also comprehends the use of individual heating units, and control means therefor, for the cleansing and sterilizing liquids to provide the desired temperature conditions.

Still another and more specific object is to pro vide for the conduction of the sterilizing liqud to the pre-rinse section so that residual heat of the sterilizing liquid is utiliz-ed, and the amount of additional heat required for pre-rinsing purposes is minimized.

A still further object of the invention is the utilization of waste heat from the heating units to ellect drying of the cleansed articles, and at the same time to contribute to the sterilization of the articles.

Still another object is to provide for drying action, just indicated, by utilizing a heat exchanger in a manner that heated air, and not the products of combustion, will be utilized to effect the drying.

The invention also comprehends the provisionl of means for exhausting moisture laden air from within the device whereby none of such air is admitted to the room within which the device is used.

The foregoing objects are primary objects which, together with other objects and advantages of the invention, will be more fully apparent from the following description considered in connection with the accompanying drawings in which:

Fig. 1 is a side elevational view of one embodiment of the invention, portions thereof being cut away to show structural details of the device;

Fig; 2 is an isometric view partly in section of one of the sections or units of the machine;

Fig. 3 is a plan view partly in section taken on line 3 3 in Fig. 1;

Fig. 4 is a vertical sectional view taken on line 4 4 in Figs. 1 and 3;

Fig. 5 is a vertical sectional view showing an alternate construction providing a' single combuston coil for heating the cleansing liquid in two of the sections or units of the device.

The embodiment shown in the drawings includes a casing l within which are sections 2, 3, 4 and 5 for respectively pre-rinsing, washing, sterilizing and drying of articles passing through the machine. The articles to be cleaned are propelled through the device as by means of conveyor chains 6 driven by the drive chain 'l from a suitable source of power (not shown). Y

Sections 2, 3 and 4 include combination tank and heater units il,` 9 and I0 respectively, and such units contain quantities of the cleansing liquor or liquids used and are operable, as will be further detailed, to maintain these liquids at the desired temperatures. For example, it is intended that the pre-rinse liquid in the unit 8 shall be maintained at a temperature of approximately F. to 140 F. This range of temperatures is such that, in the case of washing dishes the primary use of the invention, food particles and substantially all of the grease are removed in this section, and yet the temperature is not suiiciently high to x the food particles upon the articles being cleansed. In order to maintain the desired temperature there is provided a thermosta'tic control shown at 20 (Fig. 2), for controlling the rate of supply of fuel to the burner 2| (Fig. 1) in the burner or combustion chamber 22 at the bottom of the respective units.

It is intended that Athe tank of the unit 9, section 3, shall contain a suitable detergent and the liquid in such tank shall be maintained within a temperature range of approximately F. to F. and that the sterillzing liquid in unit In, section 4, shall be maintainedwithin a temperature range of F. to boiling so that effective sterilization of the articles is had.

As best seen in Fig. 2, an important feature of the invention resides in the tank and heating units 8, 9 and l0, and the structure` for their cooperation with the remainder of the device,

unit 9 being shown in this figure although it is to be understood that the units are identical except as indicated otherwise herein.

Referring specifically to the disclosure of the figure, the unit is divided into upper and lower chambers 23 and 22 respectively by the horizontal partition shown at 24. This partition comprises a peripheral portion 25 secured to the side walls of the unit, and a central inverted boxlike structure 26 opening downwardly and forming a part of the chamber 22. The ends 21 and 28 of the structure 26 are spaced from the end walls of the unit and comprise headers for a plurality of water tubes 29 through which heat is imparted from the gases of combustion in the chamber 22 to the liquid within the water tubes 29 and the tank or chamber 23. It is to be noted that the front header 21 also extends sidewardly to the side walls at 33 and that the top of the structure 26 extends forwardly and sidewardly as shown at 34 to form a chamber at the forward end of the unit 9 so that liquid withdrawn through conduit 64, as will be more fully described, must pass through the water tubes whereby heat is imparted to the liquid.

The chambers 22 and 23 are provided with removable plates and 3| at their forward ends to provide access to these chambers for such repair or cleansing as may be necessary.

As best seen in Fig. 4 the top of the structure 26 terminates at the rear of the unit in an upwardly extending portion 35 to provide a passage 36 for flue gases which enter the vent or flue 31 at the rear of the machine for conduction therefrom in a manner that will be more fully described.

Referring again to Fig. l, it is to be noted that the upper side portion of the respective units 5, 9 and I6 form a baille 46 to whichinclined aprons 4I are attached. These aprons extend sidewardly and downwardly from the respective bailles and terminate at their ends in depending flanged members 42 which provide a supporting ledge 43 for the tray 44 having a screen bottom 45 (Fig. 2) which serves to collect r.

particles that would otherwise fall into the cleansing liquid within the tank beneath.

Liquid is supplied to the machine from a single source or inlet pipe shown at 59 whence it is conducted through pipes 5| and 52 to the tanks of units 9 and l0 respectively. The tanks of the units 8, 9 and I0 have overflow pipes 53, 54 and 55 respectively. The pipe 54 of unit 9 is connected directly to a discharge drain in a well known manner. 'I'he overflow pipe 55 in the sterilizing unit III, however, communicates with the conduit 56 which terminates at 51 in pump outlets which respectively communicate with the spray heads 66 comprising U-shaped manifolds 61 at one side of the spray chambers. 'Ihe spray terminals in each section comprise tubes 19 that are integrally attached to and communicate with the interior of the manifolds 61 as seen at 66 in Fig. 4. These tubes extend transversely of the spray chambers in parallel relation and have suitable openings 69 therein so that the pumped cleansing liquid in each section is sprayed from both above and below into the area through which the articles pass under propulsion of the conveyor chains 6.

Attention is also directed to the fact that the doors 1|, 12 and 13 for the sections 2, 3 and 4, are movable vertically to open position, and that the caps 14 closing the ends of the spray tubes 10 are then readily accessible for removal so that, when necessary. a cleansing tool may be passed through these tubes to effect cleaning thereof.

Opening of any of the doors 1|, 12 and 13 likewise makes accessible the tray 44 so that any material accumulated thereon can be removed.

As already indicated, the products of combustion surrounding the water tubes 29 in the respective units 8, 9 and I0 are conducted rearwardly to the flue or vent passage 31 at the back of the machine. It is desired tn use the residual heat in these gaseous products for drying and effecting a further sterilizing action upon the cleansed articles, and yet to avoid actual contact of such gases with the articles.` To this end the vent 31 communicates with a heat exchanger comprising the coil 15 in the section 5. This coil is sinuous in form to provide adequate surface for heat exchange so that air admitted by the fan 16 to the interior of the drying section is first heated the bottom of the tank of the pre-rinse unit 8. In this manner stsrilizing liquid in the unit I6, being relatively clean and having lost some of its heat, is conducted to the pre-rinse section l where little if any additional heat is necessary to maintain the proper pre-rinse temperature conditions. 'I'he overflow pipe 53 of the unit 5 is also connected to the discharge drain and hence all cleansing liquid to be discharged from the machine is conducted through the overflow pipes 53 and 54.

'Ihe circulation of the liquids in the sections 2, 3 and 4 is produced by pumps 60, 6I and 62 driven by suitable motors (not shown). The inlets 63, 64 and 65 to these pumps are connected with the respective tanks at their forward ends whereby the inlet uld passes through .water tubes 29 preliminary to its conduction to the and then moves upwardly about the articles as they move to the left (Fig. 1) under the influence of the conveyor chains 6. It is to be understood that the heat exchanger may be of any suitable form so long as it provides for adequate transfer of heat from the heated gases to the air that is introduced to and moves upwardly within the drying chamber 5.

The exhaust end 11 of the heat exchange coll 15 extends upwardly and terminates within the flue 16 which is of sutllcient size to also serve for removing moisture laden air from within the drying chamber 5. It is intended that natural or forced draft exhaust from the flue 18 shall be suiilclent that there is a slight suction from within the machine, and 'in this manner no moisture laden aid from within the machine or cumbustion products from the burner chambers 22 is permitted to enter the room in which the machine is being used.

The overflow pipe in each of the units 6, 9 and I0 is provided with a head 36 having a horizontally disposed entrance 8| so that any material which rises to the surface of the liquid in the tank chamber tends to enter the head and to be removed from the tank.

In the operation of the machine as above described, and by way of further description thereof, it is pointed out that water is admitted through the inlet pipe 56 and distributed through pipes 5| and 52 to the tanks of units I0 and 9 respectively. The rate of admission of water, or other cleansing fluid, is desirably controlled that proper cleansing and sterilization of articles passing through the machine are effected at all times. The liquid level in the respective tanks is maintained constant as determined by the overflow heads 88, the rinse water of unit I overflowing into the unit 8 whereby the desired quantity of liquid is maintained within the latter. vThe thermostatic control for the respective units controls the rate of combustion at the burners 2| whereby the cleansing and sterilizing liquids are maintained at desired temperatures. A suitable cleansing agent or agents such as soap and the like may be added from time to time to the liquid within any of the tanks. In the preferred use of the invention, however, it is contemplated that a detergent shall be added only to the liquid Within the unit 9.

As water is controllably admitted to the respective tanks, the heating thereof is effected by combustion within the chambers 22, the products of combustion rst passing about the tubes 29 and thence to the vent or ilue passage 31. The heat conducted through the walls of the tubes 29 is instrumental in maintaining the desired temperature of the liquid within the respective tanks. 'I'he pumps 60, 6I and 6-2 are placed in operation whereby cleansing fluid is sprayed in the respective sections both upwardly and downwardly from the lower and upper groups of spray terminals or tubes 10. At the same time articles to be cleansed are moved successively through the prerinsing, washing, sterilizingand drying sections 2 to 5 inclusive so that such articles emerge from the section 5 in a sterile and-dry condition.

When cleansing articles in which temperature differentials between succeeding cleaning operations are unnecessary, the structure shown in Fig. 5 may be used. In this construction containers 85 and 86 communicate with two of the tanks of the units 8, 9 and III. A combustion coil 81 has portions extending into each of these tanks. At the inlet end 88 to this coil there is provided a mixer 89 so that a combustible mixture is admitted to, and is burned within the coil. The outlet 90 of the coil may terminate in the vent 31 or may be directly connected to the heat exchanger 15. In such manner there is a coordination of elements so that desired and intended results are accomplished.

It is emphasized that the invention comprehends a unitary structure in which all necessary operations are performed to clean and sterilize the articles passing therethrough. While specific details and temperatures have been set forth, such details are presented by way of illustration and not as limitations'as the 'invention broadly comprehends a machine for washing, drying and sterilizing articles in a continuous process, cleansing fluids being supplied in successive stages, that clean and sterile articles are withdrawn therefrom.

The invention claimed is:

1. In a machine for cleaning dishes and like articles, the combination of successive cleaning sections in which the articles to be washed are treated with cleansing liquids, each of said sections including a liquid container and heating means therefor, whereby required temperatures for the respective cleansing liquids are maintained, a heat exchanger, means for conducting heated gases of combustion from at least some of the heating means to said heat exchanger, additional means for conducting air over said heat exchanger and supplying such air to the articles leaving said cleansing divisions, and flue means,

- and sterilizing sections having aligned chambers through which the articles pass, each of said sections including a liquid container below the chamrber thereof, a fluid inlet and an overflow for each of said containers, means for admitting fresh liquid to the container of each of the washing and sterilizing sections, means to project the liquid onto the articles in each respective section and a conduit interconnecting the overflow of the sterilizing section to the inlet of the pre-rinse section.

3. In a machine for cleaning dishes and like articles, the combination of pre-rinsing, washing and sterilizing sections having aligned chambers through which the articles pass, each of said sections including a liquid container below the chamber thereof, a, uid inlet and an overflow for each of said containers, means for admitting fresh liquid to the container of each the washing and sterilizing sections, a, conduit interconnecting the overflow of the sterilizing section to the inlet of the pre-rinsing section, and additional means for maintaining the cleansing liquid in each container within a, predetermined limit of temperatures.

4. In a device of the class described, a plurality of aligned cleaning sections in which articles to be'cleaned are treated with cleansing liquids, each of said sections including a liquid container, a heating chamber vcommunicating with each of said containers and combustion means extending into at least two of said heatingchambers to impart heat to the liquid in the containers communicating therewith, said combustion means comprising a conduit for heated gases of combustion and passing sealably through the walls of the heating chambers.

JAMES N. ALLENSWORTH.

'REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 240,404 Gibbs Apr. 19, 1881 1,029,541 Haustetter June 11, 1912 1,508,828 Wholey Sept. 16, 1924 1,624,982 Rosenberg Apr. 19, 1927 1,712,728 Blakeslee et al. May 14, 1929 1,719,410 Webb July 2, 1929 2,036,503 Russell Apr. 7, 1936 2,057,681 Harrington Oct. 20, 1938 2,117,279 Anson May 17, 1938 2,190,165 Shurts Feb. 13, 1940 2,250,238 Smith July 22, 1941 2,358,507 Haberstump Sept. 19, 1944 2,368,916 Drum et al. Feb. 6, 1945 2,410,934 French Nov. 12, 1946 FOREIGN PATENTS Number Country Date 887,864 France Aug. 23. 1948 

